PDrill

The 2050 width indeed points to a Ducato (and the siblings). In my experience a transverse bed in those will be between 190 and 195 centimeters depending on the insulation and inside wall design. I'm 193cm and our previous PVC had 140x193 bed and when travelling alone it was fully ok sleeping corner-to-corner. The missus being somewhat shorter we used to sleep 'my feet in her mouth' and it was that much okay that our next van will have bed the same size.

If the heater has been working fine installed as it is, I believe the smoke is just a symptom of a soon-to-be-failing heater. At my work we repair Webasto and Eberspächer heaters which work just like the Truma D (in fact, the Truma has Eberspächer internals) and that's just how they start failing. For years everything okay, then they start to smoke (mostly durings starts) and eventually starting up fails a few times in a row and then the heater gets locked. For normal Eberspächer heaters there are a plenty of components that can be replaced to remedy the situation, don't know what's the parts policy under the Truma brand. But like I said, the countdown has begun.